Combined experimental and numerical investigation of a vortex dipole interaction with a deformable plate

Abstract

The impact of a vortex dipole with a cantilevered plate is studied experimentally in a quasi-two-dimensional environment, using a combination of flow visualization and particle image velocimetry to elucidate the flow kinematics and estimate the pressure loading on the plate. The experimental results are complemented by numerical simulations that further illuminate the attendant fluid-structure interaction and vortex dynamics. Both deformable and rigid plates are investigated at a dipole Reynolds number of 1030. Upon impact, the dipole halves split, with each half joining with surface-generated vorticity of opposite sign to form secondary structures. One half forms a secondary dipole at the plate tip, while the other advects along the plate surface and exhibits a rebounding effect, similar to the dipole impact on an infinite wall. The rate of vorticity generation is lower along the deformable plate versus the rigid one, resulting in altered secondary dipole trajectories. The experimental and numerical results are compared in terms of vortex dynamics, plate response, and plate loading, all of which are in good agreement to within experimental uncertainty. The most significant discrepancy in tip deflection occurs around the time of the dipole impact with the plate. The sensitivity of the plate response to the initial distribution of vorticity in the dipole core is also discussed.